1. Field of the Invention
The present invention relates to a shift lever device provided with a locking mechanism for use in the automatic transmission of a vehicle or the like.
2. Description of the Related Art
In a conventional shift lever device, a shift lever is rotatably supported on a housing fixed to a vehicle body, for example, as swingable in a longitudinal direction (a shifting direction) of the vehicle, and a rod is inserted into the shift lever as movable in an axial direction. By operating a knob button of a knob provided on an upper end of the shift lever, the rod is moved, and a detent engaging portion provided on a lower end thereof is disengaged from a particular detent groove provided on the housing, thus enabling the shift lever to be shifted.
A locking mechanism is provided to lock the engagement of the detent engaging portion with the P-range groove when the shift lever is at a parking position. The locking mechanism includes a locking means disposed in the vicinity of the P-range groove, which engages with the detent engaging portion and prevents disengagement thereof from the P-range groove.
In the conventional shift lever device, the operating force of the knob button is applied to the locking means via the rod. In order to bear the force, the locking means has to be firmly supported by the locking mechanism and the locking mechanism cannot be compact. Moreover, since screws and the like are used to firmly fix the locking mechanism to the housing, increases in the number of parts as well as assembly steps have been inevitable.
An object of the present invention is to provide a shift lever device with a simple construction, to contribute to reduction in the number of parts, assembly steps and production costs.
A first aspect of the present invention is a shift lever device comprising: a housing fixed to a vehicle body; a shift lever comprising a tube and a supporting member provided with a pivot rotatably supported by the housing and a base block to which the tube is connected; a knob having a knob button, being connected to the tube; a rod inserted through the shift lever, the rod being movable in an axial direction by operating the knob button; a key provided on an end of the rod, the key having a detent engaging portion for engaging with a detent plate of the housing; and a locking mechanism disposed beside the shift lever, having a lock lever with a locking portion at a tip thereof, the lock lever swingable about a predetermined axis, wherein the lock lever swings so that the locking portion is interposed between the base block and the key to lock movement of the rod, thus maintaining the engagement of the detent engaging portion with the detent plate.
Preferably, the key has a first face facing the base block, the base block has a second face facing the key, the second face is provided with a guiding hole for guiding the rod, the guiding hole being sized so as to stop the key, and the locking portion of the lock lever is inserted into and removed from a gap formed between the first face and the second face by swinging the lock lever on a plane substantially parallel to the first face and the second face. And the axis about which the lock lever swings is substantially parallel to the axial direction of the rod in the shift lever at a parking position.
And preferably, the locking mechanism is mounted on the detent plate.
According to the first aspect as described above, when the rod and the key move to a detent plate side and the detent engaging portion engages with the detent plate, a gap is created between the base block and the key. When the locking portion is interposed in this gap, the rod cannot move to the knob side no matter how the knob button is operated. Accordingly, the detent engaging portion cannot disengage, whereby the shift lever can not shift to the other position. In other words, the shift lever is put in a locked state. Since it is mainly a compression, not a shear or twist, which acts on a locking portion of the lock lever interposed in the gap, the lock lever, the locking mechanism and supports thereof can be compact and light in weight.
As described above, the secure lock of the shift lever is achieved simply by interposing the locking portion of the lock lever between the base block and the key, and the simple construction of the shift lever device contributes to a reduction in the number of parts, assembly steps and production costs.
A second aspect of the present invention is the shift lever device according to the first aspect, wherein the lock lever comprises a displacement absorber elastically deformable with respect to force acting on the lock lever.
According to the second aspect, due to an elastic deformation of the displacement absorber provided on the lock lever, the displacement of the lock lever is absorbed, when a force is applied thereon in the event of shifting the shift lever with the locking portion of the lock lever pinched between the base block and the key. Accordingly, force is not transferred to a swing axis of the lock lever, thereby protecting the locking mechanism. The driving means such as a solenoid for operating the lock lever is also protected from the force acting thereon. Thus the reliability of the locking mechanism is enhanced.
A third aspect of the present invention is the shift lever device according to the first aspect, wherein a tip of the lock portion is tapered.
According to the third aspect, the lock lever can swing to dodge the key when the key moves to the range of the lever and bumps the tip thereof.